In 1834 Jean Charles Peltier, a French watchmaker and part-time physicist, found that an electrical current would produce heating or cooling at the junction of two dissimilar metals.
Unsurprisingly, this became known as the Peltier effect and led to the development of the Peltier module, which is primarily used for making small solid-state coolers for drinks and similar applications.
Peltier modules are commonly available. The batch I found on eBay and social media tells me that enthusiasts are using them to build things such as powerful coolers for their gaming computers.
It’s a fascinating technology, but what I found really intriguing is that there is now a small company in Scotland that is using them to build a heat pump.
Thermoelectric Conversion Systems Ltd. (TCS), who are based just outside Glasgow, are manufacturing their “Hummingbird” unit based entirely on the Peltier effect.
According to TCS, this is an extremely high-performance unit with a CoP>10 and is available with a rating up to 20 Kilowatts.
Unlike conventional heat pumps, this technology is “solid state” and so requires hardly any maintenance. It has no moving parts apart from a fan and a pump.
Asking about costs, TCS say that it’s “cost competitive” with conventional heat pumps.
However, I think its simplicity will ultimately make it much cheaper. It will also be easier to install.
For example, due to the low start-up current demand, it can be run using a standard 13amp plug point. Therefore, no heavy cable installation.
What I find really interesting about this technology though is that it’s highly scalable.
I asked about the idea of using different size units upstairs and downstairs in a house to create heating zones.
TCS said they thought a typical household would have several thermoelectric heat pumps of different capacities according to the application.
They also pointed out that where their technology beats the conventional systems “hands-down” is the modulation range as it can operate anywhere between 0% and 100%, and if the power output has to be changed every 10 seconds for the whole day that simply isn’t an issue.
Intriguingly, they are also looking at having heat pumps in individual radiators, each separately controllable.
Couple this with the development of the “Passive House” standard building and it all makes a lot of sense as it could enable the building of a fully computerised domestic heat network.
Importantly, “under the covers” (on the other side of the mains power supply) as TCS puts it, this technology runs using 48V DC which is solar PV battery voltage.
So, it’s entirely suitable for off-grid customers and I understand they already have a few.
Being reversible, a Peltier device can also serve as a cooling system which, whilst not always needed in Scotland, could become a very useful feature in the future and will certainly help the company develop an export market.
As it doesn’t use any refrigerants or other gases, it’s also leak-free.
In addition, it’s a very compact piece of technology. A 6kW unit only has a footprint of 400mm x 276mm which is much smaller than a conventional heat pump.
What that means is that it’s not as limited in where it could be used as a conventional heat pump is.
It also has a high temperature range (< -30°C > 80°C) and is extremely reliable with a Mean Time to Failure of more than 300,000 hours or 30 years continuous use.
The team behind this development have all got an extensive electrical engineering background and told me that unlike engineers developing conventional heat pumps, they didn’t know Peltier devices couldn’t be made into heat pumps and so didn’t have the problem of “knowledge and dogma” getting in the way, so just got on and did it having been told by a lot of so called experts they were wasting their time.
They weren’t.
This reminds me somewhat of the current attitude of far too many in the UK towards hydrogen.
Every time someone demonstrates hydrogen working the “experts” claim that whatever it is, it’s impossible.
The point here is that we need disruptors like TCS who ignore conventional thinking and just make things work.
In this particular case, it seems likely they’ve produced a product that has the ability to make heat pumps much more appealing to the consumer, especially given it can be run off-grid.
This is a great application of a long-understood thermo-electric effect which has been cleverly exploited for a growing market.
In fact, it may well accelerate the growth of that market.
That said, this is a small company and we all know the risks that running small companies – particularly those involved in manufacturing – can involve and the biggest of these is funding.
It’s really time we sorted that issue out because we don’t want to lose any more of our innovators and disruptors. In fact, we need more of them.
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